The present invention relates to trucks and trailers and, more particularly, to wheel and axle assemblies thereof.
In the past few years, brake safety for truck and trailers has been on the forefront due to several horrific accidents prompting governments to act. As a result, automatic slack adjusters and stroke warning indicators have been provided therefor.
On the other hand, the freight industry has become increasingly competitive over the years. In some instances, the quality of materials and products has suffered as a result thereof. With stricter regulation, maintenance has been required in order to correct defective or inadequate truck/trailer axle assemblies. For instance, brake system components of trailers have been subject to frequent repairs. The brake systems typically comprise a cam shaft having an S-cam at an end thereof. The cam shaft is actuated at a free end thereof such as to be journaled in bushings secured to the axle of the trailer or truck, whereby the S-cam actuates brake shoes against a brake drum of the wheel.
According to new government ruling, the bushings need to be replaced when the cam shaft is slightly loose therein. This is to ensure a generally optimal braking, which occurs when the braking cylinder actuates the cam shaft at a 90 degree angle therewith. However, the change of bushing is costly in materials and labour as a hub holding the wheel needs to be removed to effectuate the repair. This is so because the hub interferes with the S-cam such that the cam shaft can not be pulled out of the bushings. Consequently, the hub needs to be removed. When the hub system is put back in place, it requires to be relubricated, and this also involves providing new sealing elements and lubricants to the hub. Also, the above described operation requires meticulous handling in order to avoid having abrasive particles, such as sand or dust, infiltrate the sealed hub systems. Consequently, the hub sealing is labour intensive and therefore costly.
It is a feature of the present invention to provide a hub for trucks/trailers which substantially overcomes the disadvantages of the prior art.
According to the above feature of the present invention, and from a broad aspect thereof, the present invention provides a truck/trailer hub of the type having a generally cylindrical portion defining an aperture, whereby the hub is adapted for mounting on a spindle of a truck/trailer axle such as to be free to rotate on the spindle. The hub has a flange projecting outwardly from an outer surface of the cylindrical portion. The flange comprising a plurality of throughbores therein, whereby the flange is adapted for securing a wheel of a truck/trailer thereto, such that the wheel can rotate with the hub and brake therewith when a brake member of the truck/trailer axle is actuated on a portion of the wheel by a cam shaft. The flange has at least a notch therein such that the cam shaft may be removed by pulling it through the notch without the hub requiring to be removed from the spindle.
According to a further broad aspect of the present invention there is provided a method for removing a brake actuating cam shaft from a truck/trailer axle, comprising the steps of (i) removing a wheel mounted on a hub of a truck/trailer axle; (ii) aligning a notch in the hub with the cam shaft by rotating the hub about the truck/trailer axle; and (iii) removing the cam shaft from the truck/trailer axle by pulling the cam shaft through the notch.